autfilt: fix --sat-minimize -B

Fixes #340.

* bin/common_post.cc: -B implies -S.
* tests/core/satmin2.test: Test this.

NEWS

@@ -35,6 +35,9 @@ New in spot 2.5.2.dev (not yet released)
   - Fix cryptic error message from Python's spot.translate() and
     spot.postprocess() when supplying conflicting arguments.
 
+  - "autfilt -B --sat-minimize" was incorrectly producing
+    transition-based automata.
+
 New in spot 2.5.2 (2018-03-25)
 
   Bugs fixed:

bin/common_post.cc

@@ -164,6 +164,7 @@ parse_opt_post(int key, char* arg, struct argp_state*)
     case 'B':
       type = spot::postprocessor::BA;
       colored = spot::postprocessor::Any;
+      sbacc = spot::postprocessor::SBAcc;
       break;
     case 'C':
       comp = spot::postprocessor::Complete;

tests/core/satmin2.test

@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2013, 2015, 2017 Laboratoire de Recherche et Développement
-# de l'Epita (LRDE).
+# Copyright (C) 2013, 2015, 2017, 2018 Laboratoire de Recherche et
+# Développement de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -520,3 +520,8 @@ test "`cat out`" = 1
 
 # Make sure no extra state are added.  See issue #204
 test 2 = `ltl2tgba a | autfilt --sat-minimize --stats=%s`
+
+# Make sure -B implies -S even for --sat-minimize.  See issue #340.
+ltl2tgba -G -D -f 'GF(a <-> XXb)' > aut
+test 6 = "`autfilt -B --sat-minimize --stats=%s aut`"
+test 6 = "`autfilt -B -S --sat-minimize --stats=%s aut`"